Steam assisted gravity drainage (SAGD) is a technique used to facilitate the production of hydrocarbons, such as heavy crude oil and bitumen. Horizontal wells are drilled into a reservoir containing the hydrocarbons and oriented so that one horizontal well is above the other. Steam is injected into the upper horizontal wellbore under high pressure to heat the hydrocarbons and to thus reduce the viscosity of the hydrocarbons. The heated hydrocarbons drain downwardly into the lower horizontal wellbore for production to a surface collection location.